There are a number of different circumstances in which it is necessary for a person to have an artificial airway, such as a tracheostomy tube, placed in his or her respiratory tract. As used herein, the phrase “artificial airway” includes devices such as tracheostomy tubes, endotracheal tubes and the like. Artificial airways keep the patient's natural airway open so that adequate lung ventilation can be maintained. In particular situations, the artificial airway must be left in the patient for a prolonged period of time. For example, many persons suffering severe neck or head trauma receive a tracheostomy tube in conjunction with mechanical ventilation during extended recovery and rehabilitation periods.
When an artificial airway is used, it is critical that respiratory secretions be periodically removed. This is typically accomplished by the use of a respiratory suction catheter that is advanced into and through the tracheostomy tube. As the suction catheter is withdrawn, a negative pressure (or vacuum) is applied to draw mucus and other secretions from the patient's airways and the interior of the artificial airway. While a substantial amount of mucus and other secretions will be withdrawn through the lumen of the suction catheter, a portion of the mucus and other secretions will remain as a film on the outside of the catheter.
In a closed suction catheter assembly (for example as set forth in U.S. Pat. Nos. 3,991,762 and 4,569,344), the catheter may be enveloped by a protective sleeve and include a valve mechanism disposed near the vacuum source. These features reduce the risk of contamination to both the patient and the care-giver.
In normal breathing, the structures of the nose and sinus passages serve to heat and moisturize inhaled air. In situations where a patient requires mechanical ventilation on a periodic basis, it is common to place a heat and moisture exchanger (HME) on the proximal end of the artificial airway after removal of the mechanical ventilator. This type of placement is commonly done with patients who are able to breathe on their own for an extended period of time. In such systems and as used herein, “proximal” refers to the direction toward the clinician and “distal” refers to the direction toward the patient.
The HME is intended to replicate these functions, of heating and moisturizing air, in patients having artificial airways. The HME is adapted to reduce heat and moisture loss from the respiratory system of the patient as the patient breathes. This is done by retaining within the HME heat and moisture from air which is exhaled through the HME, and by warming and moisturizing air that is inhaled through the HME. The HME typically includes a material, such as porous foam, that is enclosed within a housing or other structure.
To date, most HMEs have not been used in conjunction with a closed suction catheter assembly. Thus, prior to suctioning respiratory secretions from a patient, it may be necessary to remove the HME from the proximal end of the artificial airway so that a suctioning catheter may be advanced to the patient's natural airways. Removal and attachment of the HME often causes discomfort to the patient and, during the period in which the HME has been removed, the patient is deprived of heat and moisture exchange and may be deprived of supplemental oxygen, if used.
Thus, there is a need for an inexpensive adaptor that enables a closed suction catheter to be easily and quickly attached to and removed from an HME that is mounted to an artificial airway while minimizing patient discomfort.